Interdental cleaner

ABSTRACT

An interdental cleaner has a gripping portion (3) and a cleaning portion (4) formed by an elongate body made from a thermoplastic material. The cleaning portion (4) has a coating made of a self-adhesive, heat-vulcanized rubber material forming peripheral, flexible brush members (6).

PRIORITY CLAIM

The present application is a Continuation of U.S. patent applicationSer. No. 17/107,937, entitled INTERDENTAL CLEANER, filed Nov. 30, 2020,which is a Continuation of U.S. patent application Ser. No. 16/267,145,entitled INTERDENTAL CLEANER, filed Feb. 4, 2019, and issued as U.S.Pat. No. 10,856,958 on Dec. 8, 2020, which is a Continuation of U.S.patent application Ser. No. 15/122,137, entitled INTERDENTAL CLEANER,filed Aug. 26, 2016, and issued as U.S. Pat. No. 10,195,005 on Feb. 5,2019, which claims priority to PCT Application No. PCT/EP2014/078338,entitled INTERDENTAL CLEANER, filed on Dec. 17, 2014, which claimspriority to European Patent Application No. 14158195.9, filed on Mar. 6,2014, the content of which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to interdental cleaning devices and inparticular to an interdental cleaner having a toothpick design with abrush portion.

BACKGROUND

Various types of interdental cleaners or toothpicks have been used sincelong ago. Toothpicks of plastic materials are widely used nowadays, andan early example of an interdental toothpick is disclosed inJP-1979-170098U. In one embodiment described therein, the toothpick hasa stick-like body of hard synthetic resin which is partially coated by asoft synthetic resin. The soft material portion of the toothpick servesto remove dental plaque and the like from the teeth.

Another example of the same basic structure is shown in U.S. Pat. No.6,158,444 (corresponding to WO 98/16169), where a rod-like carrier madeof hard plastics is partially coated by a soft thermoplastic elastomer(TPE).

Further interdental cleaners of similar type are disclosed inEP-A-153,011 and U.S. Pat. No. 3,775,848 and some recent designs areshown in WO-A-2009/150964, WO-A-2012/156025, WO-A-2013/176297,WO-A-2014/005659, WO-A-2014/023395, WO-A-2014/023424, CN-U-201790907,JP-A-2013188299, JP-A-2013192866 and US-A-2014/0008837.

Certain of the interdental cleaners or toothpicks described in thesepublications are available on the market, and many of them suffer fromdifferent drawbacks which users have experienced. Some toothpicks are oftoo weak structure which means that they break in use. Other interdentalcleaners have inefficient brush portions leading to incomplete cleaningof the teeth. Furthermore, certain toothpicks are uncomfortable to gripand may slip. In summary, many prior-art interdental cleaners are hardto handle by users.

From the above it is understood that there is room for improvements.

SUMMARY

An object of the present invention is to provide a new type ofinterdental cleaner which is improved over prior art and whicheliminates or at least mitigates the drawbacks discussed above.

This object, as well as further objects which will appear from thefollowing description, have now been achieved by an interdental cleaneras defined in appended claim 1 with preferred embodiments set forth inthe dependent claims.

In a first aspect, there is provided an interdental cleaner whichcomprises a gripping portion and a cleaning portion formed by anelongate body made from a thermoplastic material. The cleaning portionhas a coating which comprises a heat-vulcanized rubber material andwhich forms peripheral, flexible brush members. An interdental cleanerof this kind is advantageous since the combination of materials and theheat-vulcanization provides a favourable balance between stiffness andflexibility. The active part of the cleaner contributes to an efficientcleaning process.

In one embodiment, the rubber material comprises a thermoset rubber,preferably a silicone based rubber which has specific favourableproperties. The heat vulcanization creates chemical crosslinks in thethermoset rubber which enhances the structure of the interdentalcleaner.

Preferably the rubber material has a Shore hardness in the range of10-60 Shore A, preferably 15-30 Shore A. The thermoplastic materialforming the body may be a polyamide or polyester which absorbs humidityfrom the oral cavity which makes the interdental cleaner more ductileand thereby less vulnerable to break. Preferably, the body is reinforcedby glass fiber in a proportion of 5-30% by weight, preferably 10-20% byweight, of the thermoplastic material.

The rubber coating can also be applied at least partially to thegripping portion in order to form a preferred relief structure on thesame. This design enhances the gripping comfort and reduces slip. Italso opens for promotional use of the interdental cleaner.

The brush members may be formed as peripheral brush flanges whichimproves the brushing at the teeth surfaces, in particular compared tomany prior-art cleaners with thin, radial, pin-like brush members whichhave only a slight contact with the teeth. Preferably, the outerdimension of the brush flanges is gradually decreasing towards the freeend of the cleaning portion, and the outer periphery of the brushflanges preferably forms a substantially circular shape. Hereby anefficient cleaning is achieved since the contact with the teeth isenhanced.

In an embodiment, the brush flanges are spaced substantially equidistantalong the cleaning portion and preferably arranged in alternate pairsalong the cleaning portion. The first pairs have two brush flangesextending radially from the axis of the cleaning portion in a firstopposite direction whereas adjacent second pairs have two brush flangesextending radially from said axis in a second opposite direction. Theangle between these directions is about 90°. This design of the activepart of the interdental cleaner is beneficial to the cleaning contactwith the teeth.

The cleaning portion body is preferably tapering towards the free end ofthe body which improves the brushing against the teeth surfaces.

Furthermore, the cleaning body portion may be provided with axialgrooves and ridges forming a kind of splines. This design improves theadherence of the coating, and it provides a brush flange arrangementwith favorable bending properties balanced with appropriate stiffness.

A cleaning portion of this kind has a very slender design which enhancesthe user's opportunity to efficiently clean the spaces between all teethin the oral cavity. If the ridges of the cleaning portion body protrudein radial directions, which coincide with the first and seconddirections of the spaced brush flanges, the advantages are even moremanifested.

The gripping portion may have a substantially rectangular cross sectiondefining two opposite, substantially flat gripping surfaces and an outerrim extending along the outer periphery of the gripping portion. Herebya comfortable gripping is achieved.

Furthermore, the gripping portion may include a transition section whichis tapered towards the cleaning portion and which further enhances thegripping.

Preferably, the axial length of the cleaning portion is in the range of35-55% of the overall axial length of the interdental cleaner, and it isalso preferred that the axial length of the gripping portion—includingthe tapered transition section—is in the range of 45-65% of the overallaxial length of the interdental cleaner. By these proportions, anefficient and comfortable teeth cleaning process can be achieved.

In an embodiment, the cross dimension of the cleaning portion at thefree end of the interdental cleaner constitutes about 40-50% of thecross dimension of the cleaning portion adjacent to the transitionsection. This design provides for a slender active part of theinterdental cleaner which enhances the user's opportunities to clean allkinds of interdental spaces in the oral cavity.

In a second aspect, an interdental cleaner is suggested which comprisesa gripping portion and a cleaning portion formed by an elongate bodymade from a thermoplastic material. The cleaning portion is providedwith a coating with a heat-vulcanized rubber material formingperipheral, flexible brush members. The heat-vulcanized rubber materialcomprises a thermoset silicone based rubber. This design is favourable,since the durability of the silicone rubber enhances the use of theinterdental cleaner.

A third aspect is directed to an interdental cleaner with a grippingportion and a cleaning portion formed by an elongate body made from athermoplastic material. The cleaning portion has a coating comprising aheat-vulcanized thermoset silicone rubber material and formingperipheral, flexible brush members. The thermoplastic material formingthe body is reinforced by fiber material or minerals. By this design,the interdental cleaner is given a favorable balance between stiffnessand flexibility which facilitates the cleaning process.

In a fourth aspect, an interdental cleaner is proposed which comprises agripping portion and a cleaning portion formed by an elongate body madefrom a thermoplastic material The cleaning portion has a coating whichcomprises a heat-vulcanized rubber material and which forms peripheral,flexible brush members in the shape of peripheral brush flanges. Theouter dimension of the brush flanges is gradually decreasing towards thefree end of the cleaning portion, and the outer periphery of the brushflanges forms a substantially circular shape. Advantages are obtained bythis design in that the brushing contact with the teeth is improved.

A fifth aspect is directed to an interdental cleaner with a grippingportion and a cleaning portion formed by an elongate body made from athermoplastic material. The cleaning portion is provided with a coatingwhich comprises a heat-vulcanized rubber material and which formsperipheral, flexible brush members. Furthermore, the cleaning bodyportion tapers towards the free end of the same and it is provided withaxial ridges and grooves. The brush members are formed as peripheralbrush flanges, the outer dimension of which is gradually decreasingtowards the free end of the cleaning portion and also forming asubstantially circular shape. In this aspect, the brush flanges arespaced substantially equidistant along the cleaning portion and arearranged in alternate pairs along the same. The first pairs have twobrush flanges extending radially from the axis of the cleaning portionin a first opposite direction and adjacent second pairs have two brushflanges extending radially from the axis in a second opposite direction.The angle between these directions is about 90°, and the ridges of thecleaning body portion protrude in radial directions which coincide withthe first and second directions of the brush flanges. This design isadvantageous since the arrangement of the brush flanges results inefficient brushing. In particular, the cleaning portion can flex incertain directions.

BRIEF DESCRIPTION OF THE DRAWING

Embodiments of the invention will be described in the following;references being made to the appended diagrammic drawings whichillustrate non-limiting examples of how the inventive concept can bereduced into practice.

FIG. 1 is a perspective view of an interdental cleaner of an embodimentof the invention.

FIG. 2 is a front view of the interdental cleaner.

FIG. 3 is a side view of the interdental cleaner.

FIG. 4 is a cross section on a larger scale along the line IV-IV in FIG.2 .

FIG. 5 is an axial, sectional perspective view of the interdentalcleaner of FIGS. 1-4 .

FIG. 6 is a sectional side view of the interdental cleaner of FIG. 5 .

FIG. 7 shows the detail of FIG. 6 on a larger scale.

FIG. 8 is a plan view of an interdental cleaner of a basic size.

FIGS. 9-11 show sections along the lines IX-IX, X-X and XI-XI in FIG. 8.

FIG. 12 is an end view XII-XII of the interdental cleaner of FIG. 8 .

FIG. 13 shows the detail of FIG. 12 on a larger scale.

FIG. 14 is a plan view of an interdental cleaner of a slightly largersize than in FIG. 8 .

FIGS. 15-17 show sections along the lines XV-XV, XVI-XVI and XVII-XVIIin FIG. 14 .

FIG. 18 is an end view XVIII-XVIII of the interdental cleaner of FIG. 14.

FIG. 19 shows the detail of FIG. 18 on a larger scale.

FIG. 20 is a sectional side view of the interdental cleaner of FIG. 8 .

FIG. 21 is a section along line XXI-XXI of FIG. 20 .

FIG. 22 is a corresponding section of the interdental cleaner of FIG. 14.

FIG. 23 is a perspective view of a substrate cleaning portion of theinterdental cleaner.

FIG. 24 is a corresponding perspective view of the complete cleaningportion.

FIG. 25 is an end view of the interdental cleaner with a tip cut awayfor illustration.

FIG. 26 shows a cross section of a prior-art interdental cleaner forcomparison.

FIG. 27 is a perspective view of a set of substrates for production ofinterdental cleaners.

FIG. 28 is a plan view of the set shown in FIG. 27 .

FIG. 29 is a perspective view of a set of complete interdental cleaners.

FIG. 30 is a plan view of the set shown in FIG. 29 .

FIG. 31 illustrates how the cleaning portion of an interdental cleanerof FIG. 8 is cleaning a gap between two front teeth.

FIG. 32 illustrates how the cleaning portion of an interdental cleanerof FIG. 14 is bent for cleaning a gap between two back teeth.

FIG. 33 shows the tip of the cleaning portion of the interdental cleanerof FIG. 32 .

FIG. 34 further illustrates the cleaning action of the interdentalcleaner of FIGS. 32-33 .

FIG. 35 is a cross section which shows how the cleaning portion of theinterdental cleaner of FIGS. 32-34 is inserted in the gap between twoback teeth.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An interdental cleaner or toothpick 1 according to an embodiment of theinvention is shown in FIGS. 1-6 , and it is formed by an elongatesubstrate or body 2 also referred to as carrier in the following. A setof bodies 2 for forming the toothpicks 1 is shown in FIGS. 27-28 . Thebodies 2 are made of a thermoplastic material, for instance amideplastics, preferably polyamide “6” or alternatively polyester, providinga favorable stiffness for the interdental cleaner 1. Preferably, thepick body 2 is reinforced by glass fiber.

The toothpick 1 has a handle or gripping portion 3, a cleaning portion 4and an intermediate transition section 5 tapering towards the cleaningportion 4. The cleaning portion 4 is provided with a coating Cconsisting of a self-adhesive, heat-vulcanized rubber material,preferably a thermoset rubber, such as a liquid, self-adhesive siliconerubber. The coating C forms peripheral, flexible brush members in theshape of brush flanges 6, the outer dimension or radial extension ofwhich is gradually decreasing towards the free end or tip 7 of thecleaning portion 4. The cleaning brush flanges 6 are spaced at the samedistance from each other (equidistant) along the cleaning portion 4.

The transition section 5 enhances the user's gripping of the toothpick 1since he/she can put his/her fingers on this section 5 when performingthe reciprocal cleaning movement. Furthermore, the transition section 5improves the stiffness and thereby the strength of the toothpick 1. Thetransition between the handle/grip and the elongate brush portion isoftentimes a weak point of prior-art interdental cleaners.

The radial extension of the brush flanges 6 is best shown in thesections in FIGS. 20-21 , where the flange 6 a closest to the grippingportion 3 has the largest radial projection whereas the flange 6 bclosest to the tip 7 of the cleaning portion 4 has the smallest radialprojection.

As is best shown in FIG. 24 , the equidistant brush flanges 6 arearranged in alternate pairs along the cleaning portion 4. The firstpairs have two opposite flanges 6F extending radially from the centeraxis CA of the cleaning portion 4 in a first opposite direction FOD andthe second pairs have two opposite flanges 6S extending radially fromthe center axis CA in a second opposite direction SOD.

Preferably, the angle between these two directions FOD and SOD is about90° forming a four-wing design of the cleaning portion 4; see FIGS. 13and 19 . The four-wing design can also be described as a four-leafclover shape seen from the tip 7 of the toothpick 1. The cross-likearrangement of the equidistantly spaced brush flanges 6 provides for avery efficient cleaning of the space between two teeth, that is when theactive cleaning part 4 of the toothpick 1 is pushed in a reciprocalmovement in this space.

The coating material C is applied also to the gripping portion 3, as canbe seen in FIG. 4 . The flexible, silicone based material C forms arelief structure on two opposite, substantially flat gripping surfaces 3a and 3 b of the gripping portion 3. The relief structure is of socalled negative type, which means that coating material C is left out incertain areas so that the surface of the underlying substrate 2 isexposed. Thereby, grooves 8-13 are formed in the coating material C onthe gripping portion 3, which form the relief structure.

Since the substrate 2 preferably is of light colour, for instance white,and the coating material C preferably is of a dark colour (cf. FIGS. 8and 14 ), the relief structure has a very clear appearance which isfavorable for promotional purposes, like exposing trademarks, logotypes,etc (like TePe®).

Furthermore, the relief structure is advantageous in that it providesfor a secure gripping of the toothpick 1 at the gripping portion 3. Asshown in FIG. 4 , the gripping portion 4 has a substantially rectangularcross section forming the two opposite gripping surfaces 3 a, 3 bprovided with the relief structure. Preferably, these two surfaces 3 a,3 b are somewhat curved inwards towards the axis of the toothpick 1 sothat two opposite concave areas are formed. This concave design, whichappears like an oval shape in FIG. 2 , further enhances the user'sgripping of the toothpick 1.

FIGS. 8-13 and FIGS. 14-19 , respectively, show two slightly differentsizes of the interdental cleaner 1, 1′ according to the general designdescribed above. The cleaning portion 4 of the toothpick 1 of FIG. 8 hasa slightly smaller diameter or cross section than the cleaning portion4′ of the toothpick 1′ of FIG. 14 . Toothpicks 1 can be delivered invarious sizes and colours depending on the requirements of the users.

In addition to the relief structure of the gripping portion 3, 3′ thetoothpicks 1 of FIG. 8 and FIG. 14 are provided with additional reliefareas 14, 14′ on opposite sides of the transition sections 5, 5′. Theserelief areas 14, 14′ further promote a comfortable gripping of thetoothpicks 1, 1′ since the user can put his/her finger tip in the smallrecess formed by the relief area 14, 14′. As described above, the reliefarea 14, 14′ is formed by exclusion of the coating material C so thatthe surface of the underlying carrier or substrate 2 is exposed.

In FIG. 23 the part 2 a of the elongate body 2 which will form thecleaning portion 4 is shown before coating. This cleaning portion body 2a is tapering towards the tip 7 and it has axial ridges 15 and grooves16 forming splines. These axial splines 15, 16 form a cross-like,four-wing or four-clover cross section which—after coating—matches thefour-wing design of the brush flanges 6, as is shown in FIG. 25 wherethe coated tip is cut away for illustration purposes. The splines design15, 16 enhances the adherence of the coating material C on the cleaningbody part 2 a and it matches the brush flange arrangement so thatfavorable bending properties balanced with appropriate stiffness areachieved.

The axial planes containing the opposite directions FOD and SOD shown inFIG. 24 coincide with the radially projecting ridges 15 of the cleaningbody 2 a, whereas the radial grooves 16 coincide with sloping recesses17 formed by the brush flanges 6. This cross-like design of the cleaningportion 4 is favourable since it enhances bending of the active brushpart of the toothpick 1 in the directions of the longitudinal recesses17 along the cleaning portion 4. It is preferred that the cleaningportion 4 can be bent up to 180° with respect to the gripping portion 3.

As is clear from FIG. 25 , the angle between two crossing planesincluding the FOD and SOD forms 90 o, whereas the recesses 17 areinbetween (45 o) between these planes. The cross-like design is furtherillustrated in FIGS. 12-13 and 18-19 , respectively.

A cross section of a prior-type of interdental cleaner IC is shown inFIG. 26 for comparison with the cross-like design shown in FIG. 25 . Theknown cleaner IC has only a few thin projecting brush members BM withlarge spaces in between. This means that only the tips of the brushmembers BM take active part in the cleaning process. Contrary to thisexisting technique, the brush flanges 6 of the interdental cleaner 1shown in FIG. 25 define an outer periphery which forms a substantiallycircular shape. This means that the contact surface between the outeredges of the brush flanges 6 is much larger for the toothpicks 1, 1′described herein. Therefore, the cleaning process performed by thesetoothpicks 1, 1′ is improved over prior art.

Certain proportions of the interdental cleaner 1 have been foundfavourable. In FIG. 3 the axial lengths of the cleaning portion 4 andthe gripping portion 3 (including the transition section 5) are shown asL1 and L2. In order to have an efficient active part, that is thecleaning portion 4, the axial length L1 thereof should be in the range35-55% of the overall length L1+L2 of the toothpick 1. Preferably, thisproportion is in the range of 40-50% and most preferred about 45%.Toothpicks 1 produced with these proportions, make it possible for theuser to perform an extended reciprocal cleaning movement; thereby takingfull advantage of the improved cleaning portion 4.

Furthermore, comfortable gripping of the toothpick 1 is achieved if theaxial length (L2) of the gripping portion 4—including the axial lengthL3 of the transition section 5—is in the range 45-65% of the overallaxial length of the toothpick 1. Preferably, this proportion is in therange of 50-60%, and most preferred about 55%.

The design of the active part of the interdental cleaner 1, 1′ isslender, as can be seen in FIGS. 21-22 . The cross dimension or diameterD2, D2′ of the cleaning portion 4 at the tip 7, 7′ constitutes about 45%of the cross dimension or diameter D1, D1′ of the cleaning portion 4adjacent to the transition section 5, 5′. The smooth tapering of thebody portion 2 a makes it possible for the user to reach behind teethand to push the toothpick 1, 1′ into all interdental spaces whencleaning the teeth. The slenderness can of course vary to some extent,and the proportion between the diameters mentioned above can be withinthe range 40-50% with very efficient result.

Returning now to the materials used, the toothpick body 2 is made from athermoplastic material, preferably a polyamide, for instance of the typepolyamide “6”, or PBT (polybutylene terephtalate). In preferredembodiments, the body 2 is reinforced by a reinforcement material. Whenglass fiber reinforcement is used, favourable properties—such assuitable stiffness—have been achieved if the glass fiber proportion ofthe toothpick body 2 is within the range 5-30% by weight, preferably10-20% by weight and most preferred 15% by weight of the thermoplasticmaterial. Certain designs of the interdental cleaner 1 with a glassfiber proportion of less than 12% by weight, in particular 5-10% byweight, have been tested in practice with favorable results.

Other types of reinforcements like carbon and aramide fibers or mineralsare feasible, as well as mixtures thereof.

The preferred coating material C for the active part—that is thecleaning portion 4—is a self-adhesive, liquid, heat-vulcanized siliconerubber which has proven good results in practical tests. This thermosetsilicone based rubber material has favourable chemical properties. Inthe heat vulcanization process, chemical crosslinks are created ascovalent bonds which cannot be broken by thermodynamic means.Preferably, the heat vulcanization is performed at a temperature ofabout 120-200° C.

Contrary to the rubber material described above, most prior-artinterdental cleaners have an active part or coating consisting of athermoplastic elastomer (TPE) with physical crosslinks which form weakbonds. When the thermoplastic elastomer is heated, the bonds are brokenwhich means that the polymer chains can move so that the material can beprocessed again. When cooling the thermoplastic elastomer, the physicalcrosslinks are formed again.

The chemical crosslinking of the silicone material used in theembodiments described herein gives the active part of the interdentalcleaner 1, 1′— that is the coating of silicone rubber—an improved tearstrength compared to prior-art cleaners.

In order to obtain favorable flexibility of the interdental cleaner 1,1′ and a comfortable cleaning process using the same, various hardnessproperties have been tested. The thermoset silicone based rubbermaterial has proven most favorable properties if the Shore hardness isin the range of 10-60 Shore A, preferably 15-30 Shore A and mostpreferred about 20 Shore A. Practical tests with this silicone rubbermaterial also showed favourable tear-off properties.

Briefly, the process of manufacturing an interdental cleaner of the typedescribed above can be performed as follows. Thermoplastic granules arefed into and melted in a heated injection unit. The melt is theninjected into the cold mold, in which it hardens and is shaped inaccordance with the cavities of the molding tool. The liquid siliconerubber (LSR) is delivered as two components: a first component A and asecond component B. One of the components contains a catalyst whereasthe other component contains a crosslinker. The silicone is not createduntil the two components are mixed. In room temperature, it takes weeksuntil the silicone is created whereas at higher temperatures thesilicone is created in a few seconds (depending on the thickness of thearticle).

The proportion of the components A and B is 1:1 and they are mixed andinjected into a heated molding tool. In the heated tool, a chemicalreaction is initiated which is called heat vulcanization—during whichthe self-adhesive silicone rubber is created.

Thus, the plastic bodies or carriers are injection molded in the coldpart of the tool. Thereafter, the bodies/carriers are moved to theheated cavities in which they are overmolded with the silicone rubbermaterial forming the aimed-at coating of the complete toothpicks.

The silicone material is a thermoset rubber which has proven to be veryuseful for this kind of manufacturing process and which has the aimed-atproperties of the interdental cleaner, in terms of adhesion to thesubstrate of the toothpick, efficient cleaning, suitable flexibility andcomfortable gripping and use. Preferable materials for the substrate towhich the coating is applied are polyamides, in particular polyamidetype “6”. As mentioned above, other substrate materials are feasible,for instance PBT.

Before the coating C is applied, a number of bodies 2 are arranged insets, as is illustrated in FIGS. 27-28 . From these figures, it can beseen that the gripping portion has an outer rim 18 which extends alongthe periphery of the same. This rim 18 defines a kind of recess 19 wherethe coating C is to be applied in the manufacturing process. The rim 19contributes to a comfortable gripping of the complete coated toothpick1. The substrates 2 are connected to each other by thin tear-off bridgesor links 20 consisting of the body material.

The links 20 are maintained in the manufacturing process and keeptogether the finished toothpicks 1 in sets of the type illustrated inFIGS. 29-30 . When a toothpick 1 is to be used, the user simply breaksthe link 20 between two adjacent toothpicks 1 and separates thetoothpick 1 to be used.

With reference to FIG. 31 , an interdental cleaner 1 of the type shownin FIG. 8 is illustrated in an initial cleaning position. Thanks to thedesign of the tapering cleaning portion 4 and a well-balancedreinforcement of the same, a suitable stiffness is achieved whichfacilitates the axially reciprocating cleaning movement in the gapbetween two front teeth 30, 31. The splines 15, 16 shown in FIG. 23 alsocontribute to the suitable stiffness. The flat rectangular grippingportion 3 provides for a secure grip by the fingers of the user so thathe/she can perform an efficient cleaning. The ingenious arrangement ofthe alternating brush flanges 6 of the cleaning portion 4 furtherenhances the cleaning. The brush flanges 6 are in tight contact with theteeth surface throughout the cleaning process.

In FIG. 32 an interdental cleaner 1′ of the type shown in 14 isillustrated in a cleaning position where it is bent and partiallyinserted between two back teeth 40, 41. The balance between stiffnessand flexibility of the tapering cleaning portion 4′, which can be bent,makes it possible to reach and conveniently clean at locations at theback of the oral cavity. Also in this bent position, the brush flanges6′ are in tight contact with the teeth surfaces so that efficientcleaning is achieved.

The four-wing brush flange arrangement of the interdental cleaner 1′ isfurther illustrated in FIGS. 33 , whereas in FIG. 34 the interdentalcleaner 1′ is shown in the perspective. In this position, the flatgripping portion 3′ is rotated about 90° compared to the position inFIG. 32 . The cleaning process can preferably involve both an axiallyreciprocating movement and a rotation about the axis of the interdentalcleaner 1′.

Finally it should be mentioned that this inventive concept by no meansis limited to the embodiments and examples described above, and manymodifications are feasible within the spirit and scope of the inventionas defined in the appended claims. For instance, specific versions ofmaterials can be used, and the specific design of the toothpicks canvary. Furthermore, the cross-sectional shape of the flanged cleaningportion may be varied depending on specific requirements. In addition tothe cross-like design, various star-like designs with several projectingsets of brush flanges can be used. An alternative design is athree-flange design which also provides favourable cleaning contact withthe teeth.

1. An interdental cleaner comprising a gripping portion and a cleaningportion, said interdental cleaner being formed by an elongate body, saidelongate body being made from a thermoplastic material and said cleaningportion having a coating which comprises a heat-vulcanized rubbermaterial and which forms peripheral, flexible brush members; wherein theelongate body includes a cleaning portion body which, when coated, formssaid cleaning portion; wherein said cleaning portion body is taperingtowards the free end of the same; and wherein said cleaning portion bodycomprises axial ridges and grooves.
 2. The interdental cleaner asclaimed in claim 1, wherein said rubber material comprises thermosetrubber.
 3. The interdental cleaner as claimed in claim 1, wherein saidrubber material has a Shore hardness in the range of 10-60 Shore A. 4.The interdental cleaner as claimed in claim 1, wherein saidthermoplastic material forming the elongate body is reinforced by glassfiber, carbon fiber, aramide fiber or minerals.
 5. The interdentalcleaner as claimed in claim 4, wherein the fiber reinforcement comprisesglass fiber in a proportion of 5-30% by weight.
 6. The interdentalcleaner as claimed in claim 1, wherein said thermoplastic materialcomprises amide plastics or polyester.
 7. The interdental cleaner asclaimed in claim 1, wherein said coating is also applied at leastpartially to said gripping portion.
 8. The interdental cleaner asclaimed in claim 7, wherein the coating applied to the gripping portionforms a relief structure on the same.
 9. The interdental cleaner asclaimed in claim 1, wherein said brush members are formed as peripheralbrush flanges.
 10. The interdental cleaner as claimed in claim 9,wherein the outer dimension of the brush flanges is gradually decreasingtowards the free end of the cleaning portion.
 11. The interdentalcleaner as claimed in claim 9, wherein the outer periphery of the brushflanges forms a substantially circular shape.
 12. The interdentalcleaner as claimed in claim 9, wherein the brush flanges are spacedsubstantially equidistant along the cleaning portion.
 13. Theinterdental cleaner as claimed in claim 9, wherein the brush flanges arearranged in alternate pairs along the cleaning portion, first pairshaving two brush flanges extending radially from the axis of thecleaning portion in a first opposite direction- and adjacent secondpairs having two brush flanges extending radially from said axis in asecond opposite direction, the angle between said directions being about90°.
 14. The interdental cleaner as claimed in claim 13, wherein saidridges of the cleaning portion body (2 a) protrude in radial directionswhich coincide with said first and second directions of the brushflanges.
 15. The interdental cleaner as claimed in claim 1, wherein thegripping portion has a substantially rectangular cross section definingtwo opposite, substantially flat gripping surfaces and an outer rimextending along the outer periphery of the gripping portion.
 16. Theinterdental cleaner as claimed in claim 1, wherein the gripping portioncomprises a transition section which is tapered towards the cleaningportion.
 17. The interdental cleaner as claimed in claim 1, wherein theaxial length of the cleaning portion is in the range of 35-55% of theoverall axial length of the interdental cleaner.
 18. The interdentalcleaner as claimed in claim 16, wherein the axial length of the grippingportion including the tapered transition section is in the range of45-65% of the overall axial length of the interdental cleaner.
 19. Theinterdental cleaner as claimed in claim 18, wherein the cross dimensionof the cleaning portion at said free end constitutes about 40-50% of thecross dimension of the cleaning portion adjacent to the transitionsection.
 20. An interdental cleaner comprising a gripping portion and acleaning portion, said interdental cleaner being formed by an elongatebody, said elongate body being made from a thermoplastic material andsaid cleaning portion having a coating which comprises a heat-vulcanizedrubber material and which forms peripheral, flexible brush members;wherein said heat-vulcanized rubber material comprises a thermosetsilicone based rubber.
 21. An interdental cleaner comprising a grippingportion and a cleaning portion, said interdental cleaner being formed byan elongate body, said elongate body being made from a thermoplasticmaterial and said cleaning portion having a coating which comprises aheat-vulcanized thermoset silicone rubber material and which formsperipheral, flexible brush members; wherein said thermoplastic materialforming said elongate body is reinforced by fiber material or minerals.22. An interdental cleaner comprising a gripping portion and a cleaningportion, said interdental cleaner being formed by an elongate body, saidelongate body being made from a thermoplastic material and said cleaningportion having a coating which comprises a heat-vulcanized rubbermaterial and which forms peripheral, flexible brush members; whereinsaid brush members are formed as peripheral brush flanges, the outerdimension of which gradually decreasing towards the free end of thecleaning portion, and wherein the outer periphery of the brush flangesforms a substantially circular shape.
 23. An interdental cleanercomprising a gripping portion and a cleaning portion, said interdentalcleaner being formed by an elongate body, said elongate body being madefrom a thermoplastic material and said cleaning portion having a coatingwhich comprises a heat-vulcanized rubber material and which formsperipheral, flexible brush members; wherein the cleaning portion body istapering towards the free end of the same and comprises axial ridges andgrooves; wherein said brush members are formed as peripheral brushflanges, the outer dimension of which gradually decreasing towards thefree end of the cleaning portion and forming a substantially circularshape; wherein the brush flanges are spaced substantially equidistantalong the cleaning portion and are arranged in alternate pairs along thesame, first pairs having two brush flanges extending radially from theaxis of the cleaning portion in a first opposite direction and adjacentsecond pairs having two brush flanges extending radially from said axisin a second opposite direction, the angle between said directions beingabout 90°; and wherein said ridges of the cleaning portion body protrudein radial directions which coincide with said first and seconddirections of the brush flanges.